Contact your health care provider right away if you have any of these warning signs:

sudden weight gain of more than two pounds within one day

severe swelling of the face, ankles, legs, or feet

severe or frequent headaches that last more than two or three hours and do not get better after taking the medication your health care provider has recommended

fainting

blurred vision, flashes of light, or spots before your eyes

pain or burning while urinating

sudden increase in thirst

dramatic increase or decrease in urination

unusual vaginal discharge

light vaginal bleeding or spotting

Very Dangerous Warning Signs

Premature Labor — Pregnancy takes about 40 weeks. If contractions cause your cervix to open earlier than normal — between the 20th and 37th week — it's called premature labor. Premature labor can be very dangerous.

The signs of premature labor include

uterine contractions — strong tightening in the abdomen — every 10 minutes or less

repeating or constant menstrual-like cramps in the lower abdomen

abdominal cramps with or without diarrhea

pelvic pressure that feels like the fetus is pushing down

increase or change in vaginal discharge

sudden gush of watery fluids from the vagina (water breaking)

feeling like the fetus is "balling up"

Signs of other dangerous problems include

heavy bleeding from the vagina

constant severe lower abdominal pain or cramps on one or both sides

dimness or blurring of vision that lasts two or three hours

dizziness or double vision

severe or continued vomiting

chills and/or fever of 101°F or more

fever of 101°F or more with pain or burning while urinating

sudden severe swelling or puffiness of the face, hands, legs, ankles, or feet, especially if you have a headache or vision change

after six months of pregnancy, the fetus moves a lot less than before

after six months of pregnancy, you think the fetus hasn't moved in eight hours or more

If you are experiencing any of these signs, contact your health care provider or go to the hospital immediately.